Closing mechanism for bottom-dump wagons



G. W. MORK CLOSING MECHANISM FOR BOTTOM-DUMP WAGONS Nov. 20, 1951 2 SHEETSSHEET 1 Filed Feb. 28, 1948 (750%: W. MoRK,

INVENTOR AIYORNEY Nov. 20, 1951 G. w. MORK 2,575,355

CLOSING MECHANISM FOR BOTTOM-DUMP WAGONS Filed Feb. 28, 1948 I 2 SHEETSSHEET 2 INVENTOR,

ATI' ORNE'Y (550%: W MOEK,

Patented Nov. 20, 1951 UNITED STATES PATENT OFFICE CLOSING MECHANISM FOR BOTTOM-DUMP WAGONS George W. Mork, South Milwaukee, Wis., assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Application February 28, 1948, Serial No. 11,985

Figure 2 is a plan view of the same. Figure 3 is an enlarged front-end view of the first embodiment of my hydraulic cylinder and locking mechanism, taken along the lines 3--3 of Figure 1.

Figure 4is a plan view taken along the lines 4-4 of Figure 3.

My invention is herein shown as applied to a wagon of the semi-trailer type, but is equally applicable to the other type.

The body usually has downwardly converging sides and ends, and its bottom is longitudinally split along the middle to form two downwardly and outwardly opening doors.

These doors are opened and closed by one or more preferably double-acting hydraulic cylinders which may be directly connected to the doors, but are more commonly indirectly connected Figure 5 is a view, similar to Figure 3, showing a second embodiment of my invention.

' Turning now to these figures, we see that H is the conventional body of a bottom-dump wagon, supported at the rear by wheels. [2, and at the front by goose-neck [3. It has two bottomdump doors M. In Figure 1, these doors are shown closed in full line, and open dotted. They open downwardly and outwardly, being pivoted i longitudinally, one on each side of the bottom thereto by a rope and tackle block in such a manner that action of the cylinders in one direction draws on the rope to close the doors and action of the cylinder in the other direction slackens the rope allowing the doors to open. In the past the doors have been held in closed position by the hydraulic cylinders. With such an arrangement, however, leakage in the cylinder or valve or any other part of the hydraulic circuit permits the doors to open gradually.

Accordingly it is the principal object of my invention to provide a simple means for locking the doors in position, such that:

(1) Pressure and attendant leakage in the hydraulic circuit is either greatly reduced, or entirely eliminated.

(2) No additional or independent control means is required to unlock the doors, unlocking occurring automatically upon reversal of the cylinder stroke.

(3) No additional mechanical elements are required.

In addition to my principal objects above stated, I have worked out a number of novel and useful details, which will be readily evident as the description progresses.

My invention consists in the novel parts and in the combination and arrangement thereof, which are defined in the appended claims, and of which two embodiments are exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

Throughout the description, the same reference number is applied to the same member or to similar members.

Figure 1 is a side elevation of a wagon embodying my invention.

of the wagon body II, as for example by hinges Turning to the first embodiment shown in Figures 3 and 4, we see that hydraulic cylinder I5 is pivotally mounted preferably at a front corner of the wagon, as at l6. In this embodiment, the cylinder is double-acting, and the fluid to actuate it is conducted by pipes I! which lead from the towing vehicle to the cylinder. The towing vehicle, pipes thereon, and control valves therefor are conventional, and hence are not shown.

Piston rod 26 of cylinder I5 is connected as at l8 to one arm IQ of a bellcrank 20 which is pivoted preferably at 2| on the other side of the wagon front. Inside the other arm 22 of bellcrank 20 is mounted as at 23 tackle block 24, preferably with multiple sheaves. Another similar tackle block 25 is mounted on the other side of the wagon front, preferably at cylinder pivot 25, as shown in full lines in Figure 3. It should be noted that, in the full-line position, bellcrank 20 abuts the side wall of wagon-body H, and hence cannot rotate counter-clockwise any further. Thus the part of body II where bellcrank 20 abuts, amounts in effect to a mechanical stop. When piston rod26 is drawn into cylinder Hi, the tackle blocks 24 and 25 are nearest together, as shown by dotted lines in Figure '3. Accordingly by reeving rope 21, by means of which the down-'- wardly swinging doors M are suspended from the wagon body, between tackle blocks 24-25, the doors are opened or closed by actuating the cylinder to move the tackle blocks respectively together or apart. I

A preferred reeving of rope 21 is to have it run from'anchorage 28 at the front of the wagon body, several times across the wagon front between tackle blocks 24 and 25, thence around front guide sheave 29 on the wagon adjacent the lip of one .01 the .doors, .thence .undersheaves 3D and 3| on the front and rear ends-respectively of that door, thence over guide sheave 32 on the rear wall of the wagon body; thence under rear and front sheaves 33, 34 on the other door, and thence around guide sheave 35 to anchorage :35 at the front of the wagon. Any equivalent reeving may, however, be substituted.

From Figure 3, it will be seen that, when my cylinder is fully extended, so that the doors are closed, then the line of force between tackle blocks 24 and 25, i. e. the line between pivot 23 and pivot 19 is just below pivot 2|, that .is :to say the linkage is just past toggle, and hence tension on rope .21, ,due to weight of the load on the doors, .now tends torholdbellcrank Z "locked against .the side wall of the wagon body, thus holding the door closed, and entirely relieving pressure on the cylinder. Not until fluid pressure the cylinder is reversed so that the *bellcrank is forced through toggle out of .its locked position, can .the -doors .be opened.

Thus we .see .thatan effective mechanical lock is provided withoutany separate unlocking control and without adding any mechanical elements (since the .bllcrankalso serves .asthe supportfor one end of the cylinder assembly, i. e. the end thatis-connected to the movable tackle block). 4

Turning :nowv toEignre'iwe see that as a second embodiment, :I employ .a single-acting cylinder 215a modifying its connection to ithe bellcrank 20a so that when the doors are closed and .bellcrank 20 .is stopped against the wagon wall, :the bellcrank is justshort of toggle position so that most .of the .weightof .the doors will be taken .up .by .the bellcrankpivotand there will be very little pressure on the cylinder and leakage will becorrespondingly small. The doors are then opened-by merely releasing pressure fluid the cylinder.

.A few definitions,.explanatory.of theabove. A toggle linkage concerns the relative position of three points. It =eomprises two hingedly connected links, actuating means to align and disalign the vhinge .point .and the not-hinged endpoints of the two links, and means actuated by the resulting alteration .of thedistance between the-two not-hinged end-points to efiect some desired result. For .example, .in. both of .applicants variants .(see.particularlyFigure.3) ,-.one link .is that portionnf .the wagon-iront extending from ,pivot .16 .to-ipivot 12.1, and theother link is that portion of bell-crank. extending from pivot 2| to pivot 23, the 'hinge point .is pivot 2|, the two nonhingedrend-points are pivots l 6 and .2 3, :the actuating means is cylinder-piston assembly 45-26, .and -the means actuated by alteration .of the distance between points "Sand 23 .is the-rope 2.1.

When a toggle ,linkage .is usedas a lock, the three points are forced by the actuating means, from their unlocked .out-of-toggle position .(as showndotted in Figure 3) into alignment (called in toggle) and then barely out of alignment beyond -(-ca1led just .past toggle; as shown in full .lines inFigur-e 3)., and there is means '(in our :case the contact between bell-crank 22 and theside wall l t) "to prevent anyfurther disalignment of the three points. The tension or com pression in the actuated means (in our case, the tension in rope 2'!) holds the linkage locked in the just-past-toggle position, even though the actuating means be then released.

In :my second variant, namely that of Figure 5, the three points approach complete alignment, but never attain it, being prevented by contact of the bell-crank with the side-wall; hence the ex- Ztreme position attained may be called just short :of toggle.

lt-will beseen that the chief difference between my two variants is that in my first variant, when the control-mechanism is in door-closed position, its toggle-linkage is stopped just past toggle, and hence the actuating means has to be double-acting, but can be released when the linkage is looked just past toggle as above described; whereas in my second variant, when the control-mechanism is in door-closed position, its control mechanism is stopped just short of toggle, and hence the actuating means can be singleacting, butmust not .be released so long as we desire 'to hold the door closed. These are the relative advantages and disadvantages of my two variants.

Having now described and illustrated two forms of my'invention, I wish it to be understood that my invention is not to be limited to the specific forms or arrangements of parts hereinbefore described.

I claim:

11. In a bottom-dump vehicle, having a main dirt-containing body and an outwardly-opening bottom closure therefor, the combination of: a lever pivoted on the, main body; a sheave journaled on the lever at a point remote from the levers pivot; a sheave journaled on the main body, the two sheaves being coplanar, and the lever being pivoted to swing in the plane of the two sheaves; a rope trained about the sheaves, and operatively connected to the closure, and of such length as to hold the closure closed to the main body when the lever-pivot is aligned substantially in toggle between the two sheaveaxles; stop-means to limit the rotation of the lever with respect to the main body, the stopmeans being so located as to engage when the lever-pivot and sheave-axles are substantially in toggle; and power means toswing the lever into stop-means-engaging position.

2. A bottom-dump vehicle according to claim 1, further characterized by the fact that the stopmeans-engaging positionis just past toggle, and that the power means is double-acting.

3. A bottom-dump vehicle according to claim 1, further characterizedby the-fact that the stopmeans-engaging position ,is just short of toggle, and that the power means is single-acting.

GEORGE W. MORK.

REFERENCES CITED The iollowingreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 748,165 Courtney Dec. 29, 1903 752,310 'Stucki Feb. 16, 1904 758,135 Harrison Apr. 6, 1904 874,577 Dodds Dec. 24, 1907 1,111,532 Frame et a1 Sept. 22, 1914 1,729,375 Ellis et al. Sept. 24, 1929 2,312,871 Brick Mar. '2, 1943 2,314,531 Wachter Mar. 23, 1943 

